Boguslaw Kryczka

Synthese de O-Glycosides d'Alcenyles Catalysée par les Complexes du Palladium(0)

Abstract Allylic carbonates reacted with carbohydrates having a free anomeric hydroxyl group in the presence of a catalytic amount of palladium(0) giving the unsaturated O-glycosides under neutral conditions with excellent yields. In the mannofuranose and ribofuranose series, the reaction was stereospecific leading only to the α and the β anomers respectively, although a mixture of α and β anomers was obtained in the glucopyranose series.

Stereoselective palladium(0)-mediated synthesis of 1,4-disaccharides

Unsaturated 1,4-disaccharides are obtained in fairly good yields by alkylation of ethyl α-O-Δ2-glycosides which have a leaving group at the position 4 with various carbohydrates having a free anomeric hydroxyl group in the presence of a catalytic amount of palladium(0).

A polymer-supported ‘one-pot’ phosphine imide reaction on cyclodextrins

Abstract The present work describes the first example of a polymer-assisted ‘one-pot’ phosphine imide reaction using a polymer-bounded triphenylphosphine. The syntheses were performed from the 6-monoazido-β-peracetylated cyclodextrin or from the heptakis-(6-deoxy-6-azido)-β-cyclodextrin and lead to, monosubstituted, polysubstituted or dimer of β-cyclodextrin in good yields (64–43%). The repeatability of the reaction and the polymer regeneration step were investigated.

Réaction de réformatsky sur les azirnes: synthesés d'aziridines esters et de pyrrolinones

Abstract Addition of Reformatsky reagents 1 to two azirines is reported. From 2-phenyl-3,3-dimethyl azirine 2 , aziridines esters 3 are obtained. 2-Phenyl-3-methyl azirine 4 gives aziridines esters 5 and diazepinones 6 . Δ-3-Pyrrolinones or 5-methylene pyrrolidones are obtained from Grignard reagents and aziridines esters 3 and 5 . The reaction mechanism is discussed; compounds 7,8,9,11 and 12 result from an aza-1-oxo-2-bicyclo-pentane (2,1,0) intermediate.

Stereoselective Palladium(0)-Mediated Synthesis of Unsaturated 1,4-Disaccharides

Abstract Unsaturated 1,4-disaccharides are obtained in quite good yields by alkylation of ethyl α-O-Δ2-glycosides, having a leaving group at C-4, with various 1-hydroxycarbohydrates in the presence of a catalytic amount of palladium(0). The reaction is regio-and-stereospecific for α-erythro enosides 3 and 5, and only stereospecific in the case of the β-threo enoside 7, alkylation occuring at C-4 and C-2 in this case.

Palladium(0)-Mediated Synthesis of Acetylated Unsaturated 1,4-Disaccharides

Abstract Alkylation of ethyl 6-O-tert-butyldiphenylsilyl-4-O-methoxycarbonyl-2,3-dideoxy-α-D-erythro-hex-2-enopyranoside (1) with various peracetylated 1-hydroxy sugars in the presence of a catalytic amount of palladium(O) gave the corresponding unsaturated 1,4-disaccharides and trisaccharides. In all cases the reaction is regio- and stereospecific according to the unsaturated moiety, alkylation occuring only at C-4 of the unsaturated carbohydrate, with overall retention of configuration.

An Easy and Efficient Access to Bis-Allyloxy-Arenes

Abstract Bis-allyloxy-arenes were prepared in very good yields by reaction of the bis-hydroxy-arene on the appropriate allyl carbonate at room temperature in the presence of a palladium(O) catalyst.

PALLADIUM(0)-CATALYZED ACCESS TO BIS-GLYCOSYLOXY-ARENES

Bis-glycosyloxy-arenes were prepared in very good yields by reaction of the bis-hydroxy-arene on the appropriate unsaturated glycosyl carbonate at room temperature in the presence of a palladium(0) catalyst.

Palladium-catalyzed synthesis of bis-glycosides of but-2-ene-1,4-diol, butane-1,4-diol, and 1,2-bis(propenyl)benzene

Palladium(0)-catalyzed reaction of various carbohydrates derived from glucofuranose, mannofuranose, ribofuranose, glucopyranose, and glucosamine, bearing a free hydroxyl group, with 1,4-bis-(methoxycarbonyloxy)but-2-ene afforded the corresponding bis-glycosides of butene-1,4-diol. Hydrogenation in the presence of palladium on charcoal of these unsaturated compounds led to the formation of the bis-glycosides of butane-1,4-diol. The condensation was successfully extended to the bis-carbonate of 1,2-bis-[(1-hydroxy)propen-2-yl]benzene and derivatives of glucofuranose, ribofuranose and glucosamine.

Corrigendum to “Enantioselective synthesis of N-heterocycles via intramolecular Pd(0)-catalysed allylic amination” [Tetrahedron 69 (2013) 9551–9556]

The authors regret that in the published paper a reference was omitted in the introduction. The amended introduction and reference are included below. The authors would like to apologise for any inconvenience caused. The groups of Helmchen have reported enantioselective intramolecular amination of allylic acetates and carbonates catalysed by Ir complexes.20aed This method gave 2-vinyl pyrrolidine and 2vinylpiperidine derivatives in good yields and ee values of >90%.